This invention relates to an apparatus and process for cooling and muffling one or more pieces of exhaust emitting industrial equipment, such as a pair of vacuum pumps.
Many types of industrial equipment, such as vacuum pumps and air compressors, work more efficiently if some means is provided for removing the heat generated by gaseous compression and friction. Because water has the capacity to absorb relatively large quantities of heat, a number of water cooling and circulating devices for cooling industrial equipment have been developed in the prior art. Basically, such water cooling devices comprise a tank or reservoir for holding a supply of water and a refrigeration unit for cooling the water to within a desired temperature range. Water in the reservoir is circulated through or around the equipment to be cooled, which may be an air compressor, vacuum pump, or plastic molding machine, and circulated back into the reservoir, where it is again cooled down by the refrigeration unit. Examples of such cooling devices are disclosed in U.S. Pat. Nos. 2,590,061, 3,365,904, 4,060,997, and 4,144,718. Such devices may include some form of automatic liquid level control for maintaining the water level in a reservoir tank to within a predetermined range. Examples of such automatic liquid level controls may be found in previously mentioned Pat. Nos. 2,590,061, 4,060,997 and 4,144,718. Moreover, such cooling devices may also include some sort of thermostatic control arrangement for maintaining the temperature of the water in the reservoir tank to within a desired temperature range. Such thermostatic controls are exemplified by the systems disclosed in U.S. Pat. Nos. 4,060,997 and 4,144,718.
However, none of the previously mentioned prior art equipment cooling devices is without shortcomings. For example, the water in the cooling unit disclosed in the U.S. Pat. No. 2,590,061 patent must be continuously circulated around the refrigerating tank of the unit by means of a separate circulation pump in order to insure that the temperature of the water in the tank is uniform, and that the reading taken by the single thermostatic probe at the bottom of the tank is truly representative of the average water temperature of the tank. Similarly, the equipment cooler disclosed in U.S. Pat. No. 4,144,718 likewise utilizes a separate pump for agitating the water in the circulating water supply system. Even inventions as recent as that disclosed in U.S. Pat. No. 4,060,997 also suggests the use of a separate pump to circulate the water through the reservoir and heat exchanger in order to equilibrate the temperature thereof. Thus, each of these patents either discloses or suggests the use of a separate, expensive, energy consuming pump to agitate water in the system to equilibrate the temperature thereof so that the thermostat system will work properly. Additionally, the thermostatic control disclosed in the U.S. Pat. No. 4,060,997 patent is undesirably complicated, being controlled by the composite electronic signal of two separate temperature probes, one of which is located on the return side of the water circulation path, the other of which is located on the supply side of this path.
The shortcomings associated with prior art cooling devices illustrate the need for a simple, inexpensive and efficient equipment cooling device which is capable of cheaply and thoroughly agitating its water supply to a uniform temperature throughout so that a simple, inexpensive thermostatic system which senses the temperature of the water at only one particular area may be employed to accurately maintain the water temperature to between a desired temperature range.
Also known in the prior art are muffling units for muffling the exhaust noises associated with various types of industrial equipment. Specifically, U.S. Pat. No. 3,856,439 illustrates a muffling unit for a portable air compressor comprising a soundproofed and air cooled shell which envelopes the compressor. Similarly, U.S. Pat. No. 3,877,842 discloses a dampening or muffling unit for a vacuum pump comprising a cavity filled with a cellular material having inefficient vibration transmission characteristics.
However, none of these references effectively converts the energy present in the hot exhaust gases into useful work.
Such prior art references clearly illustrate the need for a more efficient muffling unit which both efficiently muffles the irritating exhaust noises emanating from industrial equipment such as air pumps and compressors, and efficiently converts the energy present in the hot exhaust gases into useful work.